The theme of the University of Arizona Superfund Research Program (UA SRP) is “Hazardous Waste Risk and Remediation in the Southwest.” Our goals are to address the health effects of contaminants of concern in the U.S. Southwest (and Mexico border), and to characterize, contain, and re-mediate hazardous waste sites.

Arsenic is a naturally occurring semi-metal element found in combination with other elements in the Earth’s crust. Due to natural geologic processes, as well as human activities, arsenic can be found in soil and water. In the arid Southwest, water and soils can be impacted by wind-borne distribution of dust from arsenic-laden mine tailings (over 300,000 acres).

In the UA SRP, investigators are studying how plants can be used to stabilize tailings and limit arsenic exposure, as well as how to measure wind-blown dust from tailings and other mining operations.

Arsenic has long been known as a poison. Whether arsenic has an effect on health depends on the route, dose (how much), and duration (how long) of exposure. Exposure to arsenic via inhalation can occur as an occupational hazard, or due to proximity to dust, such as from mine tailings. Arsenic exposure can also occur through ingestion in water or food, and children can be affected by hand-to-mouth ingestion of arsenic in dirt. Worldwide, drinking water is the most prevalent route of arsenic exposure.

Short-term (acute) exposure to high levels of arsenic can produce a variety of toxic effects, including death, but is relatively rare. More problematic is the long-term (chronic) exposure to arsenic that occurs in many parts of the world. Epidemiological (population-level) studies have shown that even low-level exposure to arsenic over time is associated with various complex illnesses, including cancer. Thus, chronic, low-level arsenic exposures of are growing concern to public health.

In the UA SRP, investigators are studying how low-level arsenic affects development of bladder cancer.

The development of disease is a complex process, and it is impossible to say whether any specific person, given a specific dose, will develop that disease. Additional factors may play a role, including nutritional status/diet, exposure to other chemicals such as those found in cigarette smoke, age, gender, and genetics. In turn, arsenic exposure can affect the expression of a person’s genes, and may contribute to the development of complex diseases such as cancer.

In the UA SRP, investigators are studying how genetic variation affects who will be sensitive to arsenic exposure, and how arsenic exposure can impact the expression of genes via epigenomic changes.

Most of what is known about the relationship between arsenic exposure and disease comes from studies of adults. What is less well-known is whether people exposed to chronic, low-levels of arsenic in utero, or as young children, will grow up to develop arsenic-related diseases as adults.

In the UA SRP, investigators are studying how early-life exposure to low-level arsenic affects lung and cardiovascular development and disease.

In January, 2006, the United States Environmental Protection Agency revised the arsenic standard for drinking water, lowering it from 50 ppb to 10 ppb, in an effort to protect the public from the effects of long-term, chronic exposure. To achieve this, several thousand drinking water utilities in the United States implemented removal technologies based on sorption, so that the arsenic is transferred from the water to a solid media. Inappropriate disposal of these solids can lead to arsenic being released into the environment again. By understanding the chemical interactions of arsenic with water or solids under different conditions, we can understand how arsenic gets into water, and also how it can be effectively removed.

In the UA SRP, investigators are studying the processes that govern solid-arsenic-water reactions, in order to understand how arsenic can be contained.

Superfund Research Program

The Superfund Research Program (SRP) is a network of university grants that are designed to seek solutions to the complex health and environmental issues associated with the nation’s hazardous waste sites. The research conducted by the SRP is a coordinated effort with the Environmental Protection Agency, which is the federal entity charged with cleaning up the worst hazardous waste sites in the country.